UK Deputy Prime Minister Nick Clegg has suffered a massive blow to his authority as his Liberal Democrat party fell victim to a bloodbath in elections in England, Scotland and Wales - and probable defeat on the totemic issue of electoral reform.

The Lib Dems lost swathes of seats in former council strongholds in the north of England to Labour, while haemorrhaging support to the Scottish National Party north of the border.

A political earthquake in Scotland saw the SNP snatch at least 10 seats from Labour, increasing its share of the vote by more than 13% in the first 25 constituencies to declare and putting Alex Salmond on course for an overall majority in his second term as First Minister.

Declaring himself "delighted" with the results, Mr Salmond confirmed he will press ahead with a referendum on independence in the coming four-year term at Holyrood, saying: "Just as the people have bestowed trust on us, we must trust the people as well."

Labour gained overall control of eight councils, including Sheffield, Hull, Bolton, Stoke and Telford. Some 12 Lib Dem wards fell to Labour in Liverpool, 10 each in Manchester and Hull and nine in Sheffield - Mr Clegg's hometown.

But the 204 seats gained by Labour by 5am did not appear to be enough for leader Ed Miliband to claim a major breakthrough in his drive to steer the party back into power nationally.

And he saw his leader in the Scottish Parliament, Iain Gray, scrape back in by a wafer-thin majority of 151 as the SNP secured the bulk of the benefit of protest votes against the Conservative/Liberal Democrat coalition Government.

Labour's best results came in the Welsh Assembly, where it took Llanelli from Plaid Cymru and Blaenau Gwent from an Independent and increased its share of the vote by 10.5% in the first 20 constituencies to declare.

Energy Secretary Chris Huhne said he was not surprised by the results.

He told BBC Radio 4's Today programme: "I think it's inevitable that if you have mid-term elections, governments do badly and these are the first mid-term elections that the Liberal Democrats have had since 1945."